Theodosia Throckmorton (aka Theo) is the smart, bold 14-year-old daughter of two intrepid Egyptologists, excavating in the Valley of the Kings in 1906. When Theo and her younger brother, invention-mad Henry, stumble upon a hidden tomb and a mysterious artifact, the 'Eye of Horus', Theo unlocks the power to see and perform true magic, thus discovering a whole new world of mystery as well as danger. From her parents' home, Museum of Legends and Antiquities in the heart of Edwardian London, Theo must do battle with ancient forces, dark magic and comic chaos as she and Henry, along with their friends, street magician Will and Egyptian Princess Safiya, try to survive teenage life, get through education, and save the whole world.